Cloth feed for sewing machines



Sept. 19, 1950 F. STALDER CLOTH FEED FOR SEWING MACHINES Filed Dec. :5, 1947 Patented Sept. 19, 1950 CLOTH FEED FOR SEWING MACHINES Fritz Stalder, Zurich, Switzerland Application December 3, 1947, Serial No. 789,388 In Switzerland September 24, 1947 1 Claim. (Ci. 112-215) The joining of two pieces of material of the same pattern, especially of striped design, by means of the sewing machine, so that the pattern of one piece of material is not displaced at the joint in relation to the other piece of material, can only be carried out successfully if the pieces of material to be used are tacked to each other with the pattern in corresponding position, before being sewn together on the machine. If they are not first tacked together, it is found that the lower piece of material directly adjacent to the feed of the sewing machine is fed more quickly than the upper piece of material. Upon sewing together two untacked pieces of cloth a relative displacement of the two patterns is produced, which displacement increases with the length of the seam, and this should be avoided in the manufacture of articles of clothing.

In order to save the time list in preliminary tacking when sewing together two pieces of material of the same pattern, the present invention provides a sewing machine feed which ensures uniform feed of the upper and lower pieces of material when sewing two pieces of material together.

This is achieved in accordance with the invention by providing the cloth feed with at least one spike which pierces the two pieces of material to be fed.

In the drawing a typical embodiment of the invention is shown as follows:

Fig. 1 a front view of those parts of a sewing machine which co-operates with the feed, with a cross-section through the needle-plate and the feed.

Fig. 2 a lateral view corresponding to Fig. 1 with a longitudinal section through the needleplate and feed.

Fig. 3 a view of the needle-plate and feed in plan,

Fig. 4 a view of the feed in plan.

In the case of the typical embodiment shown, I designates the needle-plate of a sewing machine provided with three recesses 2, 3 and 4 for the passage of the cheeks 5, 6 and l of a feed 8. Between the recesses 3 and 4 the needle-plate hole 9 for the passage of the machine needle I is located. The check is provided with feed teeth, whilst the two cheeks 6 and I each have a needle-point, H and I2 respectively, directed upwards. The needle-points II and I2 are arranged one behind the other in the direction of movement of the feed, namely one in front of, and one behind, the machine needle. The points or spikes II and I2 project 1-2 mm. above the checks or the needle-plate but their length must be such that upon the return of the feed they are entirely withdrawn from the material. To

prevent the points from being knocked off by the cloth presser foot l3 fastened to the cloth presser rod I2, the presser foot is provided underneath with a longitudinal groove l5 in alignment with the two needle-points H and I2, in which groove the points can move freely when the feed is in motion. The points or spikes H and i2 may be welded in corresponding holes in the checks 6 and l or secured by means of retaining screws l6 laterally screwed into said cheeks.

When two pieces of material a and b are sewn together, the points H and I2 pierce both pieces of material on the advance movement of the feed and impart exactly the same rate of feed to both parts. The engagement of the points H and I2 prevents in particular the upper piece of material from being fed at a slower speed owing to friction between itself and the presser foot.

Instead of the embodiment shown, the feed could also be provided with only one needle-point. It is of greater advantage, however, to provide the feed with two or more points. Of course, the cheeks 6 and i could also be provided with teeth, in addition to the points II and I2. The teeth may be entirely omitted, however, and the feed provided with points only.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that some changes may be made in the arrangement, construction and combination of the various parts of my invention, and it is my intention to cover by my claim such changes as may reasonably be ineluded within the scope thereof.

I claim as my invention:

In a feeding mechanism for sewing machines, a feed dog having a serrated upper face and two spikes adapted to pierce the two pieces of material to be fed and being arranged one behind the other in the direction of feed, one of said spikes being located in front of, and the other behind, the machine needle, and a cloth presser foot provided underneath with a longitudinal groove in alignment with said two spikes for clearing said spikes.

FRITZ STALDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS- Number Name Date 228,918 Morley June 15, 1880 986,224 Schenck Mar. 7, 1911 1,088,605 McCollum Feb. 24, 1914 1,397,071 Becker Nov. 15, 1921 

